Hi all, my car is still stock with the exception of underdrive pulleys. I was looking at a cold air kit or x pipe next (waiting on gears for now). I was wondering how much hp gain will I get changing out the stock exhaust for a xpipe
You can expect about 10 hp out of just an x-pipe. As far as the Cold Air Induction goes, either make your own (use the search function, there is a thread or two on making them I believe), or just remove the air silencer and put a K&N filter in the stock box.
You'll gain some HP for sure but dont expect to feel a WHOLE lot. A lot of the HP you gain is captured mostly in the upper RPM range where our cars dont like going when stock.
The exhaust will help more when you open up the intake side.